Hydrochloric Acid → Memantine

HRID 899573

Reaction equation

HRID 899573 reaction equation
Br[C:2]12[CH2:11][C:6]3([CH3:12])[CH2:7][CH:8]([CH2:10][C:4]([CH3:13])([CH2:5]3)[CH2:3]1)[CH2:9]2.[NH2:14]C(N)=O.Cl>C(O)=O>[NH2:14][C:2]12[CH2:11][C:6]3([CH3:12])[CH2:7][CH:8]([CH2:10][C:4]([CH3:13])([CH2:5]3)[CH2:3]1)[CH2:9]2

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 1176UreaHCID 983171-Bromo-3,5-dimethyladamantane

Product 1

HCID 4054Memantine

Reagents, catalysts & solvents 1

HCID 284Formic AcidSolvent

Conditions

Temperature
80 °C

Procedure

To 100 g of 1-bromo-3,5-dimethyl adamantane and 86 g of urea, adding 80 ml of 80 wt % formic acid, heating to 80° C. and holding for 3 hours. Cooling to the room temperature and adding 95 ml of concentrated hydrochloric acid to hydrolyze at 80° C. for about 1 hour. Adjusting with 30% sodium hydroxide to a pH of 12, extracting with toluene twice, combining the organic layers and washing with water. Concentrating under reduced pressure to yield a limpid yellow solution as the 1-amino-3,5-dimethyl adamantane crude. To the crude, adding 150 ml of ethanol and concentrated hydrochloric acid, heating to dissolve and crystallizing to yield white solid. Drying the solid and re-crystallizing with ethanol to yield 61.0 g of pure Memantine Hydrochloride. The yield of product is 68.8% (GC 99.5%).

Workup

  1. temperatureCooling to the room temperature
  2. waitto hydrolyze at 80° C. for about 1 hour
  3. extractionAdjusting with 30% sodium hydroxide to a pH of 12, extracting with toluene twice
  4. washwashing with water
  5. concentrationConcentrating under reduced pressure

Sources & evidence

ORD record
ord-af27ba54084b434ead7b5cf9d1b0792c
Source dataset
uspto-grants-2008_04
Patent number
US07355080B2

Linked notes

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